The invention relates to an electrical machine, in particular an electric motor wherein the electrical machine has a first number of commutator laminates and brushes, wherein the commutator laminates are arranged distributed uniformly in the circumferential direction on a circumference of a laminate support.
DE 695 13 655 T2 describes two windshield wiper motors for two speeds in each case. One of the two motors has two poles and three brushes, with a high-speed brush being arranged offset through a circumferential angle of, for example 120° with respect to a common grounding brush. Here, the circumferential angle is chosen as a function of a desired ratio between a high speed and a low speed of the motor. The other motor has four poles and six brushes, with the high-speed brush being arranged offset through a circumferential angle of, for example, 60° with respect to the associated grounding brush, and with the circumferential angle also being chosen here as a function of the desired ratio between a high speed and a low speed of the motor. It has been found that the operation of such conventional motors can lead to high power losses in upstream electronics, to voltage fluctuations in a vehicle power supply system, and to electromagnetic interference (EMC problems). This is particularly the case when a wave winding is used, and the number of brushes is less than the number of poles.